We use ours only for slicing bread. Because you don't saw at the bread like you do with a conventional knife it's much easier to get nice parallel slices. We've had both corded and cordless and found the corded one (ie, plugged into the mains) better.
I received one as a wedding present 43 years ago. Still sharp and going strong. The only meat I wont use it for is cutting poultry breast. Because the dual
Blades are quite wide they tend to shred and powder the meat. Beef and pork is easier to cut thinly. I would sooner use a long thin knife to slice bread but ok for thick slices of French bread. 9/10
I find that they tear the meat or bread - just ensure that you have a reasonable quality carving or bread-knife and that they are sharp - we have a great service in the market every two weeks for sharpening knives and very reasonable too - 15p an inch as the actress said to the bishop....
We’ve got one but haven’t used it in years. Much prefer a good sharp knife these days, although we used it a lot at one time.
Used to make our own bread but had to stop as we’d just eat it, warm.